Tertiary amines such as benzyldimethylamine have been utilized both as curing agents for epoxy resins and as catalysts for the anhydride curing of epoxy resins.
It has now been found that when epoxy compounds are cured with a special organic dibasic acid in the presence of tertiary amines the resulting cured resins exhibit a flexible, clear, heterophase composition with unexpectedly good impact resistance and high elongation after yield.